The present invention relates to a freeze protection and irrigation system for individual trees and especially to freeze protection system which can be supported in the earth adjacent a tree and has a rigid pipe extending to just above the tree for spraying water onto the tree.
In the past, it has been common to provide a wide variety of systems for protecting orchard trees, such as citrus trees, from occasional freezing temperatures which can damage the fruit and kill the tree. The most common system is probably to cover the trees to protect the plants from frost while providing heaters under the cover or, alternatively, providing irrigation water under the tree covers. There have also been systems for insulating tree trunks with wrapped insulating material and for pumping steam or heat into a grove under each tree and for using large wind machines to move the warmer air into colder pockets. At one time it was common to use smudge pots placed in citrus groves in order to produce heat and a cloud cover to protect the trees during short cold spells but this produced considerable pollution harmful to humans and animals and this has been widely discontinued. A large number of freeze protection systems enclose the tree foliage in large plastic or cloth covers and, in some cases, a covered framework encloses the tree. These systems sometimes require elaborate means to get the covering material over the tree foliage especially on larger trees and they are sometimes used in conjunction with heating systems.
It has become common in recent years to turn on sprinklers during freezing weather to continuously sprinkle citrus trees so that the water covering the foliage freezes and the foliage and limbs become covered with ice. The ice then acts as insulation for the foliage. The ice is held at a constant 32.degree. F., so the foliage and limbs are held at this temperature which is safe for the foliage and prevents the surrounding temperature, which may drop well below the 32 degrees from damaging the trees. This system has sometimes been accomplished with overhead tree sprinkler systems using rotary sprinkler heads covering a wide area. This has the disadvantage that the tree foliage is not uniformly and evenly covered and, in addition, freezing temperatures are frequently accompanied by high winds which tend to further reduce the coverage of the sprinkler head.
The present invention is directed towards a freeze protection system for citrus trees and the like for spraying the tree during freezing weather to insulate the trees and foliage from dropping much below the 32.degree. F. temperature level and includes a multiprong stand with a vertically extended rigid pipe having a specially designed sprinkler head on the top to spray the tree from over the foliage using low pressure water from an irrigation system. The rigid vertical pipes attached to the stands can be attached to the tree for stability and can be extended with pipe sections to any height desired. The multiprong stand portion has a step for driving the stand into the earth and can be rapidly attached to a tree and connected to an exiting irrigation system.
Prior U.S. patents which shows either a frost prevention system which sprays water above trees or an irrigation system which sprays water over the trees in a citrus or other grove or orchid or a combination of the two can be seen in the U.S. Pat. No. 3,563,461 to Cole, Jr.; the Dunlap U.S. Pat. No. 1,058,566; the Huffaker U.S. Pat. No. 1,846,395; the Hammell U.S. Pat. No. 1,991,851; the Darr U.S. Pat. No. 3,314,191; the Day U.S. Pat. No. 4,614,055; the Lilly U.S. Pat. No. 4,651,465; the James U.S. Pat. No. 4,763,440; the Heenan et al. U.S. Pat. No. 3,825,186; and the Lloyd U.S. Pat. No. 1,632,611. The Cole patent connects an irrigation pipe adjacent to a tree to be protected and telescopes up to any height to extend just above the tree to spray the tree. The Dunlap patent runs a rigid pipe directly up into the tree adjacent the tree trunk for spraying the tree. The Hammell patent has a special spray head while the Lilly patent runs a rigid pipe through some insulation adjacent a tree trunk and then has a special spray head for spraying over the tree for protecting the plant from freeze damage. The James patent has a screened enclosure for the plants and sprays them to prevent freeze damage. The Nelson U.S. Pat. No. 2,631,061; the Schwartz U.S. Pat. No. 3,599,917; the Villelli U.S. Pat. No. 4,095,744; the Clark U.S. Pat. No. 2,852,307; the Miller et al. U.S. Pat. No. 2,711,927; and the Richey U.S. Pat. No. 2,694,600 each show stands for vertical pipes or for sprinkler heads and each provided with multiprongs or a single prong and a foot step for driving the stem into the ground. These patents, however, are primarily for sprinkler systems for yards or irrigation which can be rapidly moved from place to place and supported in the ground to sprinkle a particular area. The Nelson patent however has a pair of ground insertion prongs with a foot step which also acts to block the stand from going too deep into the ground.
In contrast, the present invention is designed for rapidly converting an existing underground irrigation system into a freeze protection system which can also be used to irrigate the trees but allows a water pipe to be rapidly inserted adjacent a tree and supported on the tree to extend to just above the tree. It is directed directly over the tree for uniform even coverage and the existing irrigation system can be rapidly connected to the stand to supply water to the freeze protection system.